The minimum number of cards to be dealt from an arbitrary shuffled deck of 52 cards to guarantee that 3 cards are from the same suit are?

Here they want us to calculate the possible combinations of getting 3 cards from the same suit.
1 suit has 13 cards.
So you want to select 3 cards from any set of the 4 sets (hearts, clubs, spades, diamonds) containing 13 cards each.
As you have to make a selection of 3 cards from 13 cards.
The answer would be, \[{^{13}C_3}\]

Actually, my bad!
As there are 4 such suits, there is a possibility that you may get it from either of the 4 sets of 13 cards. So the final answer would actually be: \[^{13}C_3 + ^{13}C_3 + ^{13}C_3 + ^{13}C_3 ~~or~~ 4 * ^{13}C_3\]
Getting this? :)